Information carrying card comprising a cross-linked Polymer composition, and method of making the same

ABSTRACT

The disclosure provides a cross-linkable polymer composition, a core layer for an information carrying card comprising such cross-linked composition, resulting information carrying card, and methods of making the same. An information carrying card includes a body defining a first cavity and a second cavity. The first cavity has a first area and the second cavity has a second area. The first cavity is continuous with the second cavity and the second area is less than the first area. A circuit element is disposed within the first cavity.

This application is a continuation of U.S. patent application Ser. No.15/007,517, filed on Jan. 27, 2016, which is a continuation of U.S.patent application Ser. No. 13/648,805, filed Oct. 10, 2012 (now U.S.Pat. No. 9,275,321; granted on Mar. 1, 2016), which claims the benefitof U.S. Provisional Application No. 61/619,700, filed on Apr. 3, 2012,which applications are expressly incorporated by reference herein intheir entireties.

FIELD OF THE INVENTION

The disclosure relates to information carrying cards such as smartcards. More particularly, the disclosed subject matter relates to apolymer composition, an information carrying card comprising suchcomposition, and a method of making the same.

BACKGROUND OF THE INVENTION

Information carrying cards provide identification, authentication, datastorage and application processing. Such cards or parts include keycards, identification cards, telephone cards, credit cards, bankcards,tags, bar code strips, other smart cards and the like. Counterfeitingand information fraud associated with traditional plastic cards causestens of billions of dollars in the losses each year. As a response,information carrying cards are getting “smarter” to enhance security.Smart card technologies provide solutions to prevent fraud and decreaseresulting losses.

Information carrying cards often include an integrated circuit (IC)embedded in a thermoplastic material, such as polyvinyl chloride (PVC).Information has been input and stored in the integrated circuit before atransaction. In use, information carrying cards work in either a“contact” or “contactless” mode. In contact mode, an electroniccomponent on the card is caused to directly contact a card reader orother information receiving device to establish an electromagneticcoupling. In contactless mode, the electromagnetic coupling between thecard and the card reading device is established through electromagneticaction at a distance, without the need for physical contact. The processof inputting information into the IC of the information carrying cardalso works in either of these two modes.

When information carrying cards become “smarter,” the amount ofinformation stored in each card often increases, and the complexity ofthe embedded IC's also increases. The cards also need to withstandflexing to protect sensitive electronic components from damage as wellas offer good durability during use. A relatively easy and full-scalecommercial process having improved productivity at low cost is alsodesired.

SUMMARY OF THE INVENTION

The invention provides a cross-linkable polymer composition, a corelayer for an information carrying card comprising such cross-linkedcomposition, an information carrying card formed from the core layer foran information carrying card comprising such cross-linked composition,and methods for making the same.

In some embodiments, a cross-linkable polymer composition comprises acurable base polymer resin in a liquid or paste form, and a particulatethermoplastic filler. Such base polymer resin is selected from the groupconsisting of urethane acrylate, silicone acrylate, epoxy acrylate,acrylate, and urethane. Examples of acrylate include but are not limitedto methacrylate. The particulate thermoplastic filler may be polyolefin,polyvinyl chloride (PVC), a compound or blend comprising PVC or a vinylchloride copolymer, a copolymer of vinyl chloride and at least anothermonomer, or a polyester such as polyethylene terephthalate (PET). The atleast another monomer in the vinyl chloride co-polymer may be vinylester, vinyl acetate or vinyl ether in some embodiments. Thecross-linkable polymer composition may further comprise at least onecurative.

In other embodiments, a cross-linkable polymer composition comprises acurable base polymer resin in a liquid or paste form, and a particulatethermoplastic filler comprising a copolymer of vinyl chloride and atleast another monomer. The at least another monomer may be vinyl ester,vinyl acetate or vinyl ether. The curable base polymer is selected fromthe group consisting of urethane acrylate, ester acrylate, siliconeacrylate, epoxy acrylate, acrylate, silicone, urethane and epoxy.Examples of acrylate include but are not limited to methacrylate. Suchcross-linkable polymer composition may further comprise at least onecurative. Such a composition is transformed into a cross-linked polymercomposition after a curing reaction.

In yet other embodiments, a core layer for an information carrying cardcomprises a cross-linked polymer composition, which comprises a basepolymer resin and a particulate thermoplastic filler. Such base polymerresin is selected from the group consisting of urethane acrylate, esteracrylate, silicone acrylate, epoxy acrylate, acrylate, silicone,urethane and epoxy. The particulate thermoplastic filler may bepolyolefin, polyvinyl chloride (PVC), a compound or blend comprising PVCor a vinyl chloride copolymer, a copolymer of vinyl chloride and atleast another monomer, or a polyester such as polyethylene terephthalate(PET). A core layer for an information carrying card may furthercomprise an inlay layer having at least one active or passive electroniccomponent, e.g., an integrated circuit (IC). In some embodiments, thecross-linked polymer composition directly contacts the at least one ICon the inlay layer. In additional embodiments, an information carryingcard comprises a core layer and a cross-linked polymer composition asdescribed above.

A method for forming a core layer of an information carrying card isprovided by the invention. In one embodiment, the method comprises stepsof forming a first thermoplastic layer having at least one cavity,disposing an inlay layer of printed circuit board (PCB) partially orfully into the at least one cavity, and dispensing a cross-linkablepolymer composition over the inlay layer in the at least one cavity. Insome embodiments, the cross-linkable polymer composition used in such amethod comprises a curable base polymer resin in a liquid or paste formand a particulate thermoplastic filler. In other embodiments, a methodof making a core layer further comprises fixing an inlay layer to afirst thermoplastic layer using an instant adhesive. In furtherembodiments, a method of making a core layer further includes the stepof heating the layer structure at a predetermined temperature underpressure.

The invention also provides a method for fabricating an informationcarrying card comprising forming a core layer of the informationcarrying card of the invention. The method may further comprise heatlaminating a printable thermoplastic film and a transparentthermoplastic film on each side of the core layer of the card.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read in conjunction with the accompanying drawings. Itis emphasized that, according to common practice, the various featuresof the drawings are not necessarily to scale. In some instances, thedimensions of the various features are arbitrarily expanded or reducedfor clarity. Like numerals denote like features throughout thespecification and the figures.

FIGS. 1-6 illustrate cross section views of layered structures atdifferent steps in an exemplary process of forming a core layer of aninformation carrying card, in accordance with some embodiments.

FIG. 1 illustrates a cross section view of a first release film.

FIG. 2 illustrates a cross section view of a second release filmdisposed over the first release film of FIG. 1.

FIG. 3 illustrates a section view of a first thermoplastic layer havingat least one cavity disposed over the two release films of FIG. 2.

FIG. 4 is a cross section view of the layers after an inlay layer isdisposed partially or fully inside the cavity of the first thermoplasticlayer of FIG. 3.

FIG. 5 is a cross section view of the layers of FIG. 4 after acrosslinkable polymer composition is dispensed over the inlay layerinside the cavity.

FIG. 6 is a cross section view of the resulting layers after placing athird and a forth release film over the layers of FIG. 5.

FIG. 7 is a flow chart diagram illustrating an exemplary process offorming a core layer of an information carrying card, in accordance withsome embodiments.

FIG. 8 is a cross section view of an exemplary core layer of aninformation carry card, which is fabricated according to the structurein FIG. 1-6 and steps in FIG. 7.

FIG. 9 is a cross section view of an exemplary core layer of aninformation carry card having a full open cavity for an inlay, inaccordance with some embodiments.

FIG. 10 is a top down view of the exemplary core layer of an informationcarry card of FIG. 9.

FIG. 11 is a cross section view of an exemplary core layer of aninformation carry card having an open inlay cavity close to the size ofan inlay, in accordance with some embodiments.

FIG. 12 is a top down view of the exemplary core layer of an informationcarry card of FIG. 11.

FIG. 13 is a cross section view of an exemplary core layer of aninformation carry card having a window cavity partially for an inlay, inaccordance with some embodiments.

FIG. 14 is a top down view of the exemplary core layer of an informationcarry card of FIG. 13.

FIGS. 15-18 illustrate an exemplary process for fixing an exemplaryinlay layer onto a thermoplastic layer using an instant adhesive, inaccordance with some embodiments.

FIG. 15 is a top down view of an exemplary inlay layer, in accordancewith some embodiments.

FIG. 16 illustrates a top down view of the exemplary inlay layer of FIG.15 after cut with holes in its supporting layer.

FIG. 17 illustrates a top down view of the exemplary inlay layer of FIG.16 disposed over a thermoplastic layer.

FIG. 18 illustrates a top down view of the exemplary inlay layer of FIG.17 which is fixed onto the thermoplastic layer using instant adhesive,in accordance with some embodiments.

FIG. 19 is a flow chart diagram illustrating an exemplary process offixing an inlay layer onto a thermoplastic layer, in accordance withsome embodiments.

FIGS. 20-24 illustrate cross section views of the layer structure atdifferent steps of an exemplary process of making an exemplaryinformation carrying card, in accordance with some embodiments.

FIG. 20 is a cross section view of a transparent film.

FIG. 21 is a cross section view of a printable film disposed over thetransparent film of FIG. 20.

FIG. 22 is a cross section view of the layer structure after anexemplary core layer is disposed over the two films of FIG. 21.

FIG. 23 is a cross section view of the resulting layer structure after asecond printable film is disposed over the layer structure of FIG. 22.

FIG. 24 is a cross section view of the resulting layer structure after asecond transparent film is disposed over the layer structure of FIG. 23.

FIG. 25 is a flow chart diagram illustrating an exemplary process ofmaking an exemplary information carrying card.

FIG. 26 is a schematic drawing illustrating an exemplary core layerstructure for a plurality a plurality of information carrying cardsduring an exemplary manufacturing process, in accordance with someembodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

This description of the exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. In the description, relativeterms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,”“below,” “up,” “down,” “top” and “bottom” as well as derivative thereof(e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should beconstrued to refer to the orientation as then described or as shown inthe drawing under discussion. These relative terms are for convenienceof description and do not require that any apparatus to be constructedor operated in a particular orientation. Terms concerning attachments,coupling and the like, such as “connected” and “interconnected,” referto a relationship wherein structures are secured or attached to oneanother either directly or indirectly through intervening structures, aswell as both movable or rigid attachments or relationships, unlessexpressly described otherwise.

For brevity, unless expressly stated otherwise, references to“information carrying card” or “smart card” made throughout thisdescription are intended to encompass at least key cards, identificationcards, telephone cards, credit cards, bankcard, power cards, tags, barcode strips, any part comprising an integrated circuit (IC), and thelike. “Information carrying card” or “smart card” also includes a widevariety of shapes, which include but are not limited to rectangularsheets, circular sheets, strips, rods and rings. “Information carryingcard” or “smart card” also includes any information carrying parts ofboth “contact” and “contactless” modes. “Information carrying card” or“smart card” also encompasses any information carrying cards with orwithout an on-board power supply. An information carrying cardcomprising a power supply is also referred as a “power card.”

1. Cross-Linkable Polymer Composition:

A cross-linkable polymer composition formed in accordance with theinvention often comprises a curable base polymer resin, in a liquid orpaste form, and a particulate thermoplastic filler. The base polymerresin may be selected from the group consisting of urethane acrylate,ester acrylate, silicone acrylate, epoxy acrylate, acrylate andurethane. The acrylate may be a methacrylate. The particulatethermoplastic filler may be polyolefin, polyvinyl chloride (PVC), acopolymer of vinyl chloride and at least another monomer, or a polyestersuch as polyethylene terephthalate (PET). The particulate thermoplasticfiller may be a compound or a blend comprising a thermoplastic resin,for example, a compound or a blend comprising PVC or a vinyl chloridecopolymer. The at least another monomer in the vinyl chloride co-polymermay be vinyl ester, vinyl acetate or vinyl ether.

The base polymer resin may be an oligomer or pre-polymer havingfunctional groups. The base polymer may be cross-linkable under aregular curing conditions including but not limited to heating,radiation such as ultraviolet (UV) light, moisture and other suitableconditions. The base polymer may be in liquid or paste form. Itsviscosity may be in the range of 1-100,000 cps. In some embodiments, thebase polymer resin is urethane acrylate. These polymer resins arereadily available from specialty chemical suppliers. Examples of thesesuppliers include but are not limited to Dymax Corporation ofTorrington, CT and Sartomer USA, LLC of Exton, Pa.

A particulate thermoplastic filler suitable for the invention may be anypolymer which, when heated, will melt. Examples of a thermoplasticfiller include, but are not limited to polyolefin, PVC, polyester,copolymer, terpolymer and the like. A powdered polymer that providesadequate results may be a compound or a blend comprising PVC, or amodified PVC. One suitable example of the particulate thermoplasticfiller comprises a copolymer of vinyl chloride and at least anothermonomer, which may be vinyl ester, vinyl acetate or vinyl ether. Theratio of vinyl chloride and the least another monomer can be in anyratio. Examples of such a copolymer are available from Dow ChemicalCompany under trade name of UCAR™, and from BASF of Ludwigshafen,Germany under trade name of Laroflex™. UCAR™ is a copolymer of vinylchloride and vinyl acetate. The grades include YYNS-3, VYHH and VYHD.Laroflex™ is a copolymer of vinyl chloride and vinyl isobutyl ether. Thegrades include MP25, MP 35, MP45 and MP60. All of these polymer resinsare often supplied in the form of fine powder. One example of athermoplastic filler is a PVC modified with a copolymer of vinylchloride and at least another monomer such as vinyl ester, vinyl acetateor vinyl ether. In such an example, the ratio of PVC and the copolymercan be in the range of 99:1 to 1:99, and in the range of 95:5 to 80:20in some embodiments.

Particulate thermoplastic filler might be obtained through suspension oremulsion polymerization of one or more corresponding monomers or,through pulverization of solid plastics. Pulverization of the solidpolymers may be achieved through a mechanical method, a freezinggrinding method, a solution method, or any other suitable method. Theparticulate form can be of any size, by way of example and nolimitation; the particles may be in the range of 0.5-200 microns. Insome embodiments, the particles are in the range of 1-1000 nm.

The cross-linkable polymer composition may further comprise at least onecurative based on general principles of polymer chemistry. In someembodiments, the composition comprises a dual curing mechanism. Forexample, the cross-linkable composition comprises a first curative forthermal curing and a second curative for radiation curing. During thecuring or cross-linking reaction, such a cross-linkable compositiontransforms into a solid cross-linked polymer composition. Such across-linked polymer composition is also known in the art as a“thermosetting” polymer or “thermoset” to distinguish it from athermoplastic polymer. In some embodiments, the cross-linkable polymercomposition comprises a range of from about 20 wt. % to about 99.5 wt.%, and preferably in the range of about 50 wt. % to about 95 wt. %, ofthe base polymer. The cross-linkable polymer composition often comprisesa range of about 0.5 wt. % to about 80 wt. %, and preferably in therange of about 5 wt. % to about 50 wt. %, of the particulatethermoplastic filler. In some embodiments, the cross-linkable polymercomposition comprises a range of from about 65 wt. % to about 99.5 wt.%, and preferably in the range of about 80 wt. % to about 95 wt. %, ofthe base polymer. The cross-linkable polymer composition often comprisesa range of about 0.5 wt. % to about 35 wt. %, and preferably in therange of about 5 wt. % to about 20 wt. %, of the particulatethermoplastic filler.

In some embodiments, a cross-linkable polymer composition comprises acurable base polymer resin in a liquid or paste form, and a particulatethermoplastic filler comprising a copolymer of vinyl chloride and atleast another monomer. The at least another monomer can be vinyl ester,vinyl acetate or vinyl ether. One example of a thermoplastic filler is aPVC modified with a copolymer of vinyl chloride and at least anothermonomer such as vinyl ester, vinyl acetate or vinyl ether. The ratio ofPVC and the copolymer can be in the range of 99:1 to 1:99, and in therange of 95:5 to 80:20 in some embodiments. The curable base polymer isselected from the group consisting of urethane acrylate, ester acrylate,silicone acrylate, epoxy acrylate, silicone, acrylate, urethane andepoxy. The base polymer resin may be an oligomer or prepolymer havingfunctional groups. The base polymer may be cross-linkable under regularcuring conditions including, but not limited to heating, radiation suchas ultraviolet (UV) light, moisture and other suitable conditions. Thebase polymer may be in liquid or paste form. Its viscosity may be in therange of 1-100,000 cps. In some embodiments, functional acrylate such asurethane acrylate is preferred. In other embodiments, the base polymerresin might be epoxy, silicone and urethane. In some embodiments, aformulation for flexibilized or flexible epoxy is preferred over a rigidepoxy. Such polymer resins are readily available from the specialtychemical suppliers.

EXAMPLES

The following examples are only intended to illustrate embodiments inaccordance with the invention, and as such should not be construed aslimiting the scope of the claims.

The following examples include a thermoplastic filler (Powder 1) and aformulation comprising a base polymer resin. Powder 1 is a fine powdermechanically pulverized from a 14 mil thick poly(vinyl chloride) (PVC)film. One example of a PVC film that provides an adequate Powder 1 isobtained from KlÖckner Pentaplast GmbH & Co. KG of Germany under thetrade name Pentacard PVC (Vinyl) films, which is a PVC modified with acopolymer of vinyl chloride and vinyl acetate. The powder was sievedwith a 1.0-0.05 mm sieve before use. A formulation comprising a basepolymer resin is from Dymax Corporation of Torrington, Conn. Examples ofsuch a formulation comprising a base polymer include Multi-cure®9-20676, 9-20557 and 6-625-SV01. Multi-cure® 9-20676 is visible light orUV-curable urethane acrylate formulation comprising isobornyl acrylate,urethane methacrylate oligomer, acrylate oligomer, 2-(2-ethoxyethoxy)ethyl acrylate, 2-hydroxyethyl methacrylate, acrylic acid, t-butylperbenzoate and a photoinitiator. Its viscosity is 400 cP, and itsboiling point is 205° C.

Multi-cure® 9-20557 is a urethane acrylate or acrylated urethaneformulation comprising isobornyl acrylate, urethane methacrylateoligomer, 2-(2-ethoxyethoxy) ethyl acrylate, 2-hydroxyethylmethacrylate, acrylic acid, t-butyl perbenzoate and a photoinitiator.Its viscosity is 2300 cP, and its boiling point is 120° C. It isUV/visible light curable with secondary heat curing feature.

Multi-cure® 6-625-SV01 is a urethane acrylate or acrylated urethaneformulation comprising isobornyl acrylate, urethane methacrylateoligomer, 2-hydroxyethyl methacrylate, acrylic acid, maleic acid,t-butyl perbenzoate, a photoinitiator and epoxy resin (<1%). Itsviscosity is 10, 000 cP. It is UV/visible light curable with secondaryheat curing feature.

Exemplary formulations Ex. 1 -4 are shown in TABLE 1.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Multi-cure ® 9-20676 85% 80%Multi-cure ® 9-20557 85% 80% Powder 1 15% 20% 15% 20%

The formulations were made by mixing Powder 1 with the correspondingbase polymer at the ratio specified in Table 1. The formulation wasdegased and then placed into a syringe for easy dispensing before use.These formulations (Ex. 1-4) were used in making a core layer for aninformation carrying card, and the trials were successful. The structureof the core layer of an information carrying card, and the method ofmaking the same are described in detail hereinafter. An inlay layer of aprinted circuit board (PCB) is partially or fully disposed into the atleast one cavity of a first thermoplastic layer, which was PVC or PVCmodified with a vinyl chloride (VC) copolymer in these experiments. Oneof these cross-linkable polymer compositions (Ext. 1-4) was dispensedover the inlay layer, and then cured at a raised temperature of lessthan 150° C. under a pressure of less than 2 MPa. The resulting corelayer was used in fabricating an information carrying card. In some ofthese experiments, the information carrying card is a powered smartcard.

As comparison, the base polymer Multi-cure® 9-20676 or 9-20557 withoutany fillers was used in the same way, but the trials were not successfulin making an information carrying card.

Exemplary formulations Ex. 5-6 are shown in TABLE 1. Formulations Ex.5-6 were made using the same method as described. These formulations(Ex. 5-6) were used in making a core layer for an information carryingcard, and the trials were successful.

TABLE 2 Ex. 5 Ex. 6 Multi-cure ® 6-625-SV01 50% 20% Powder 1 50% 80%

2. Core Layer for Information Carrying Card

In some embodiments, a core layer for an information carrying cardcomprises a cross-linked polymer composition. The cross-linkedcomposition is made through curing the cross-linkable polymercomposition described above. Such a cross-linked polymer compositioncomprises a base polymer resin and a particulate thermoplastic filler.The base polymer resin is urethane acrylate, ester acrylate, siliconeacrylate, epoxy acrylate, acrylate, silicone, urethane, epoxy or thelike. The particulate thermoplastic filler may be polyolefin, polyvinylchloride (PVC), a compound or a blend comprising PVC or a vinyl chloridecopolymer, a copolymer of vinyl chloride and at least another monomer,or a polyester such as polyethylene terephthalate (PET). The at leastanother monomer in the vinyl chloride co-polymer may be vinyl ester,vinyl acetate or vinyl ether in some embodiments. One example of thethermoplastic filler is a PVC modified with a copolymer of vinylchloride and at least another monomer.

The core layer for an information carrying card further comprises aninlay layer having at least one active or passive electronic component,e.g., an integrated circuit (IC). In some embodiments, the inlay layermay comprise a piece of metal, ceramic or plastics. In some embodiments,the cross-linked polymer composition directly contacts at least one ICon the inlay layer. The core layer for an information carrying cardfurther comprises at least one thermoplastic layer having at least onecavity. The inlay layer having at least one integrated IC is partiallyor fully disposed inside the cavity over the at least one thermoplasticlayer. The crosslinked polymer composition is disposed into the cavityover the at least one thermoplastic layer, directly contacting the atleast one active or passive electronic component, e.g., an integratedcircuit (IC) on the inlay layer. This invention also provides a methodfor forming such a core layer of an information carrying card.

Referring to FIGS. 1 and 2, first release film 2 may be a sheet ofpolytetrafluoroethylene under the trade name Teflon®, any otherfluoropolymer, silicone, a fluoropolymer or silicone coated films. Asecond release film 4 is disposed over first release film 2. Secondrelease film 4 can be formed from the same material and process as firstrelease film 2. In some embodiments, a breathable release film ispreferred. Examples of a breathable release film as second release film4 is a silicone coated paper. For example, second release film 4 maytake the form of a silicone coated, unbleached parchment baking paper,available from Regency Wraps company under the trade name of “If youcare.”0

Referring to FIG. 3, a first thermoplastic layer 6 has at least onecavity 7, which is disposed over release films 2 and 4. Examples ofmaterials that are suitable for use in forming first thermoplastic layer6 include polyvinyl chloride (PVC), a copolymer of vinyl chloride,polyolefin, polycarbonate, polyester, polyamide, acrylonitrile butadienestyrene copolymer (ABS), and the like. First thermoplastic layer 6 maybe a PVC, a copolymer of vinyl chloride and another monomer such asvinyl ether, vinyl ester or vinyl acetate, or a PVC modified with avinyl chloride copolymer. Examples of PVC films suitable for use withthe invention are available from suppliers such as Klockner Pentaplastof America, Inc. of Gordonsville, Va.; and Shijiazhuang Eurochem Co. Ltdof China. Examples of such a vinyl chloride copolymer resin areavailable from Dow Chemical Company under trade name of UCAR®, and fromBASF of Ludwigshafen, Germany under trade name of Laroflex®. UCAR® is acopolymer of vinyl chloride and vinyl acetate. The grades includeYYNS-3, VYHH and VYHD. Laroflex® is a copolymer of vinyl chloride andvinyl isobutyl ether. The grades include MP25, MP 35, MP45 and MP60. Allof these polymer resins may be supplied as fine powder. A powder ofthese copolymers can be added to modify PVC resins for films. Firstthermoplastic layer 6 having at least one cavity can be formed bydie-cutting one or more thermoplastic film and then laminating andheating one or more thermoplastic films. For example, a 0.35 micronthick film is die-cut to have at least one holes, and then laminatedonto a 0.025 micron thick film to form a first thermoplastic layer 6having at least one cavity.

Referring to FIG. 4 an inlay layer 8 may be disposed partially or fullyinside cavity 7 of first thermoplastic layer 6. Inlay layer 8 comprisesat least one printed circuit board (PCB) having at least one active orpassive electronic component 10 embedded or surface-mounted on asupporting film 12. Examples of supporting film 12 include but are notlimited to polyimide, polyester such as PET, glass filled epoxy sheetsuch as FR-4. A printed circuit board (PCB) having all the componentsare abbreviated as PCBa. For brevity, the references to PCB in thisdisclosure will be understood to encompass any PCBs including PCBa.Examples of electronic component 10 inside inlay layer 8 include but arenot limited to active or passive electronic components, e.g., anintegrated circuit (IC), a battery for a “power card,” an antenna, and afunctional component such as light emitting diodes (LED). Electroniccomponents are interconnected via wires or traces 14. Supporting film 12may be a polymer based dielectric material. In some embodiments, inlaylayer 8 may comprise a piece of metal, ceramic or plastics. For example,a piece of metal or ceramic may comprise platinum, copper, tungsten,metal powders, ceramic, or ceramic powders. Inlay layer 8 may have anydimension relative to the size of a cavity in first thermoplastic layer6. Inlay layer 8 may be partially or fully disposed in such a cavity. Insome embodiments, the size of the cavity on first thermoplastic layer 6is larger than the size of inlay layer 8. Inlay layer 8 may be fullydisposed in the cavity. In some embodiments, the size of the cavity infirst thermoplastic layer 6 is the same as or slightly larger than thesize of inlay layer 6 of PCB. The shape of the cavity often matches withthe shape of inlay layer 8. In some embodiments, the size of the atleast one cavity on first thermoplastic layer 6 is less than the size ofinlay layer 8. The size of the at least one cavity is the same as orslightly larger than a portion of inlay layer 8 of the PCB. For example,the shape and size of one cavity may match with one electronic component10. Examples of electronic component 10 include but are not limited to abattery or an active or passive electronic component, e.g., anintegrated circuit (IC) in inlay layer 8.

Referring to FIG. 5, the resulting layer, after a cross-linkable polymercomposition 16, is dispensed over the inlay layer inside the cavity. Thecross-linkable polymer composition 16 comprises a curable base polymerresin in a liquid or paste form, and a particulate thermoplastic filler.Such a base polymer resin may be urethane acrylate, silicone acrylate,epoxy acrylate, acrylate, urethane, epoxy or silicone. The particulatethermoplastic filler may be polyolefin, polyvinyl chloride (PVC), acopolymer of vinyl chloride and at least another monomer, or a polyestersuch as polyethylene terephthalate (PET). The at least another monomerin the vinyl chloride co-polymer filler may be vinyl ester, vinylacetate or vinyl ether in some embodiments. The particulatethermoplastic filler may be a compound or a blend comprising athermoplastics such as PVC or a PVC copolymer. One example of thethermoplastic filler is a PVC modified with a copolymer of vinylchloride and at least another monomer. Cross-linkable polymercomposition 16 may further comprise at least one curative. Such across-linkable polymer composition 16 becomes a solid cross-linkedcomposition after curing. Preferably, such a cross-linked composition ismore flexible than the first thermoplastic layer 6 in some embodiments.

Cross-linkable polymer composition 16, which is packed in a syringe, canbe dispensed using the standard dispensing apparatus or equipment foradhesives, encapsulants, sealants and potting compounds. The amount tocross-linkable composition 16 to be dispensed can be calculated andcontrolled based on the volume of the cavity and the inlay layer 8.

Referring to FIG. 6, the resulting layers after placing a third and aforth release film over the layers shown in FIG. 5, form a sandwichstructure. The third and fourth release films can be any kind of releasefilms, and in some embodiments, second and third release films 4 areformed of the same material. The first and fourth release films 2 aremay also be formed from the same materials. For example, in someembodiments, the second and third release films 2 may be formed from abreathable silicone coated paper. The first and fourth release films 4are often formed from a fluoropolymer such as polytetrafluoroethyleneoften offered under a trade name of Teflon®. The resulting sandwich orlayered structure of FIG. 6 is placed under pressure and heated to forma core layer for an information carrying card, as illustrated in theexemplary process of FIG. 7.

Referring to FIG. 7, a process 70 forming a core layer of an informationcarrying card, in accordance with some embodiments includes thefollowing steps. At step 22, a second release film 4 is placed above afirst release film 2. At step 24, a first thermoplastic layer 6 havingat least one cavity is formed. In some embodiments, the firstthermoplastic layer 6 is formed through steps of die-cutting one or morethermoplastic films; and then hot laminating with one or more uncutthermoplastic films. At step 26, first thermoplastic layer 6, having atleast one cavity, is placed above first and second release film (4 and6). At step 28, an inlay layer 8 having printed circuit board (PCB) isplaced at least partially into the at least one cavity on firstthermoplastic layer 6. In some embodiments, the size of the at least onecavity on first thermoplastic layer 6 is larger than the size of theinlay layer 8 of the PCB. In some embodiments, the size of the at leastone cavity on first thermoplastic layer 6 is substantially the same asthe size of the inlay layer 8 of PCB. In other embodiments, the size ofthe at least one cavity on first thermoplastic layer 6 is substantiallythe same as the size of a portion of the inlay layer 8 of PCB.

Following step 28, the process optionally comprises step 30 of “fixing”inlay layer 8 on first thermoplastic layer 6 using an instant adhesive.A plurality of holes is formed on the inlay layer by cutting someportions of supporting film 12 without any electronic component 10 andinterconnects 14. An instant adhesive is applied to the holes after step28. Examples of an instant adhesive include but are not limited tocyanoacrylate. In some embodiments, inlay layer 8 is fixed to firstthermoplastic layer 6 in a period as short as a few seconds.

At step 32 (FIG. 7) a cross-linkable polymer composition 16 is dispensedover inlay layer 8 and inside the cavity. The cross-linkable polymercomposition may directly contact the electronic components 10 includingactive or passive electronic components, e.g., an integrated circuit(IC). The amount of cross-linkable polymer composition is predeterminedand controlled. Any extra material exceeding the top surface of firstthermoplastic layer 6 may be removed. In some embodiments, the curablebase polymer resin in the cross-linkable polymer composition is urethaneacrylate, and the particulate thermoplastic filler in the cross-linkablepolymer composition is PVC, a compound or a blend comprising PVC or avinyl chloride copolymer, or a copolymer of vinyl chloride and at leastanother monomer such as vinyl ester or vinyl ether.

At step 34, third release film and fourth release film 4 are placed onthe layered structure to form a sandwich structure (FIG. 6). The thirdrelease film is placed first followed by the fourth release film. Insome embodiments, the third release film is formed from the samematerial as the second release film 4, which is preferably a breathablerelease film. The fourth release film may be formed from the samematerial as first release film 2. In some embodiments, the first andfourth release films are a polytetrafluoroethylene (under the trade nameTeflon® sheet. At step 36, the layered structure above is placed underpressure, e.g., a pressure of less than about 2 MPa.

At step 38, the layered structure is heated under pressure. A suitabletemperature would be one that is sufficiently high to partially or fullycure the cross-linkable polymer composition 16, or hot laminating firstthermoplastic film 6, or both. After the heat treatment, thecross-linkable polymer composition 16 forms a solid. Such a cross-linkedpolymer composition has good adhesion with first thermoplastic layer 6and inlay layer 8 including electronic component 10 and supporting film12. In some embodiments, such a cross-linked composition is moreflexible than first thermoplastic film 6. In some embodiments, thetemperature is in the range of 65-232° C. In some embodiments, thetemperature is less than 150° C.

Process 70 may further comprise cooling the layer structure and peelingoff the first, second, third and fourth release films. Process 70 mayfurther comprise a step of curing the cross-linkable polymer composition16 using visible light, UV or other radiation curing. It may alsocomprise a step of curing via the introduction of moisture or thepromotion of other chemical reactions. After process 70, thecross-linkable polymer composition 16 is cured so as to yield a solid.After the release films are peeled away, a core layer for an informationcarrying card is formed. The core layer comprises a first thermoplasticlayer 6, an inlay layer 8 and a cross-linked polymer composition 16. Theexemplary core layers for an information carrying card from process 70are shown in FIG. 8-14.

Referring to FIG. 8, an exemplary core layer 80 of an information carrycard, is fabricated according to the structure depicted FIG. 1-6 andsteps of FIG. 7. More particularly, the exemplar core layer 80 comprisesa first thermoplastic layer 6, an inlay layer 8, and a cross-linkedpolymer composition 16. First thermoplastic layer 6 is polyvinylchloride (PVC), a copolymer of vinyl chloride, polyolefin,polycarbonate, polyester, polyamide, acrylonitrile butadiene styrenecopolymer (ABS), or the like. Cross-linked polymer composition 16 isformed from a cross-linkable composition as described in relatedsections above. Inlay layer 8 comprises electronic components 10, forexample, at least one printed circuit board (PCB), supporting film 12and interconnects 14. The electronic components, such as a battery andan active or passive electronic components 10, are connected withinterconnects 14. Electronic components 10 are embedded on supportingfilm 14. The cross-linked polymer composition fills the voids andremaining spaces inside the cavity on first thermoplastic layer 6 andinlay layer 8. In some embodiments, the cross-linked polymer compositiondirectly contacts the outer surface of electronic components 10.Referring once again to FIG. 4, inlay layer 8 may have any dimensionrelative to the size of a cavity in the first thermoplastic layer 6.Inlay layer 8 may be partially or fully disposed into such a cavity.

Referring to FIGS. 9-14, different configurations of core layers for aninformation carrying card may also be utilized with good effect.Referring to FIG. 9, an exemplary core layer 82 of an information carrycard includes a full open cavity for an inlay. In FIGS. 9 and 10, thesize of a cavity on the first thermoplastic layer 6 is larger than thesize of inlay layer 8. In some embodiments, such a cavity is close tobut slightly smaller than the size of an information carrying card.Inlay layer 8 is fully disposed into the cavity. The shape of the cavitymay not be the same as the shape of inlay layer 8.

Referring FIGS. 11 and 12, an exemplary core layer 86 of an informationcarry card includes an open inlay cavity close to the size of an inlaylayer 8. In FIGS. 11 and 12, the size of a cavity on the firstthermoplastic layer 6 is the same as or slightly larger than the size ofinlay layer 8. The shape of the cavity matches with the shape of inlaylayer 8. In this configuration, inlay layer 8 can be fully disposedinside the cavity on the first thermoplastic layer 6. The gap betweenthe edge of the first thermoplastic layer 6 and inlay layer 8 might besmaller than the gap shown in FIGS. 9 and 10.

Referring to FIGS. 13 and 14, an exemplary core layer 90 of aninformation carry card includes a window cavity partially for an inlay.In FIGS. 13 and 14, the size of the at least one cavity on the firstthermoplastic layer 6 is less than the size of inlay layer 8. The sizeof the at least one cavity is the same as or slightly larger than aportion of inlay layer 8. In some embodiments, a portion of inlay layeris cut open for form one or more holes so that an electronic component10 can be fit into one of the holes. Examples of such an electroniccomponent 10l include but are not limited to a battery or a chip in theinlay layer 8. In some embodiments, the electronic component 10 in inlaylayer 8 is inserted from one side of the first thermoplastic layer 6.During the fabrication process, a cross-linkable composition for thecross-linked polymer composition 16 can be applied to from the otherside of the first thermoplastic layer 6.

Referring to FIGS. 15-19, an exemplary process 120 fixing an exemplaryinlay layer 8 onto a thermoplastic layer 6 using an instant adhesive, inaccordance with some embodiments, includes the following steps listed inFIG. 19. An inlay layer is first provided. Referring to FIG. 15, anexemplary inlay layer 8 is used as a model for demonstration purpose.The electronic components used for a core layer of an informationcarrying card are not limited to the components illustrated in FIG. 15.Inlay layer 8 comprises a supporting film 12, a battery 102, a chip 104having at least one integrated circuit (IC), metal structures 106, metalinterconnect wires 108, and functional components such as LED 109.Supporting film 12 is a polymer based dielectric material in someembodiments. This inlay layer is suitable for a “power card.”

In step 122 (FIG. 19), a plurality of holes are formed by cutting theinlay layer 8 on the portions of the supporting film 12 without anyelectronic components and interconnect wires.

Referring to FIG. 16, the exemplary inlay layer 8 includes a pluralityof holes 112 in its supporting layer 12 after cut. The holes can be ofany shape and any size. Examples of the shape of the holes include butare not limited to circle, rectangle, square or any other shape.

In step 124, the resulting inlay layer 8 having holes is placedpartially or fully inside a cavity of the first thermoplastic layer 6.The exemplary inlay layer 8 may have any dimension relative to size of acavity in the first thermoplastic layer 6. The exemplary inlay layer 8may be partially or fully disposed into such a cavity. Referring to FIG.17, the exemplary inlay layer 8 having a plurality of holes is disposedover a first thermoplastic layer 6 having an open inlay cavity. Theexemplary first thermoplastic layer has a cavity bigger than the inlaylayer so that the inlay layer is fully disposed into the cavity on thefirst thermoplastic layer 6.

In step 126 of FIG. 7, a small amount of an instant adhesive is appliedinto each hole 112. Referring to FIG. 18, the exemplary inlay layer 8 isfixed onto the thermoplastic layer 6 using an instant adhesive 115 formthe resulting structure 116, in accordance with some embodiments.Examples of an instant adhesive 115 include but are not limited tocyanoacrylate. In some embodiments, the instant adhesive 115 cures fastin a few seconds. Such a fixing process used in this disclosure isunderstood to encompass any process of fixing an inlay layer 8 onto thefirst thermoplastic layer 6 using any other adhesive.

3. Information Carrying Cards

In some embodiments, an information carrying card comprises a core layerand a cross-linked polymer composition described above. In someembodiments, the information carrying card further comprises at leastone printable thermoplastic film laminated onto the surface of the atleast one thermoplastic layer and the cross-linked polymer composition.The information carrying card further comprises at least one transparentfilm laminated onto the surface of the printable thermoplastic film. Insome embodiments, the information carrying card comprises at least onebattery interconnected with the at least one integrated circuit (IC) onan inlay layer in the core layer. The information carrying card may alsocomprise a piece of metal, ceramic or plastic materials in the corelayer of some information carrying cards.

In some embodiments, the invention also provides a method forfabricating an information carrying card. The method comprises forming acore layer of the information carrying card in this disclosure. Themethod may further comprise heat laminating a printable thermoplasticfilm and a transparent thermoplastic film on each side of the core layerof the information.

Referring to FIGS. 20-25, an exemplary process 150 of making anexemplary information carrying card includes the following steps asshown in FIG. 25. The layer structure at different steps of an exemplaryprocess 150 is shown in FIGS. 20-24. Referring to FIG. 20, a transparentfilm 132 is provided first. A transparent film 132 can be used as theouter layer of an information carrying card. Examples of transparentfilm 132 include but are not limited to PVC, modified PVC and PET. Instep 152 of FIG. 25, referring to the structure shown in FIG. 21, aprintable thermoplastic film layer 134 is disposed onto the transparentfilm 132. The printable thermoplastic film 134 is an imaging receivinglayer. Words or images can be printed onto the printable thermoplasticfilm 134l before or during a process of making an information card. Insome embodiments, this film is not transparent, and contains somepigments such as white pigments.

In step 154 of FIG. 25, a core layer 80 is disposed onto the printablethermoplastic layer 134 and the transparent film 132. One example ofresulting layer structure is shown in FIG. 22. Referring again to FIG.8, in some embodiments, an exemplary core layer 80 comprises a firstthermoplastic layer 6, an inlay layer 8, and a cross-linked polymercomposition 16. Inlay layer 8 comprises electronic components 10, forexample, at least one printed circuit board (PCB), supporting film 12and interconnects 14. The electronic components, such as a battery andan active or passive electronic components 10, are connected withinterconnects 14. Electronic components 10 are embedded on supportingfilm 14. Cross-linked polymer composition 16 fills the voids andremaining spaces inside the cavity on first thermoplastic layer 6 andinlay layer 8. In some embodiments, cross-linked polymer composition 16directly contacts the outer surface of electronic components 10.

In step 156 (FIG. 25), a second printable thermoplastic layer 134 isdisposed onto the layered structure of FIG. 22, followed by a secondtransparent film 132.l The exemplary resulting layer structures areshown in FIG. 23 and FIG. 24. In some embodiments, at least one releasefilm is used on each side of the layer structure of FIG. 24. Referringto FIGS. 1 and 2, examples of the release film include a sheet ofpolytetrafluoroethylene, any other fluoropolymer, silicone, afluoropolymer or silicone coated films. In some embodiments, abreathable release film is used.

In step 158 (FIG. 25), the exemplary layer structure after step 156 islaminated under a pressure at a raised temperature. The layeredstructure after step 156 is pressed under a pressure. In someembodiments, the pressure is less than 2 MPa. The layered sandwichstructure is then is heated at a raised temperature under the pressure.A suitable temperature is sufficiently high so that all the films arelaminated with good adhesion. In some embodiments, the temperature is inthe range of 65-232° C. In some embodiments, the temperature is lessthan 150° C. The information carrying card may have different sizes. Insome embodiments, the information card may have a size following ISO/IEC7810 standard. For example, an ID-1 type smart card, which is for mostof the banking card and ID cards, has a size of 85.6×53.98 mm.

In some embodiments, the exemplary process 150 comprises a process suchas surface treatment to improve adhesion between two layers. Examples ofsurface treatment methods include but are not limited to plasmatreatment or corona treatment before hot lamination at step 158.

The exemplary processes 70 and 150 can be used to make a plurality ofinformation carrying cards on one sheet, in accordance with someembodiments. Referring to FIG. 26, in such process, a firstthermoplastic layer 6 comprises a plurality of cavity, in which an inlaylayer 8 is disposed partially or fully into each cavity. Referring toFIG. 26, like items are indicated by like reference numerals, anddescriptions of the structure, provided above with reference are alsodescribed above.

An exemplary core layer structure 180 comprising a plurality of inlaylayer 8 can be fabricated using process 70 as described above. In someembodiments, each inlay layer 8 is fixed onto the first thermoplasticlayer 6 with an instant adhesive 115 using an exemplary process 120(FIG. 19). Each inlay layer 8 is cut with a plurality of holes before aninstant adhesive 115 is applied. Referring again to FIG. 8, in someembodiments, an exemplary core layer 80 also comprises a cross-linkedpolymer composition 6. Inlay layer 8 comprises electronic components 10,for example, at least one printed circuit board (PCB), supporting film12, and interconnects 14. Cross-linked polymer composition 16 fills thevoids and remaining spaces inside the cavity on first thermoplasticlayer 6 and inlay layer 8. In some embodiments, Cross-linked polymercomposition 16 directly contacts the outer surface of electroniccomponents 10.

Referring again to FIG. 5, a crosslinkable polymer composition 16 isdisposed over the inlay layer inside each cavity to form the crosslinkedpolymer composition. A crosslinkable polymer composition 16 comprises acrosslinkable polymer resin and a thermoplastic filler. An exemplarycrosslinkable composition comprises a base polymer resin and aparticulate thermoplastic filler. The base polymer resin is urethaneacrylate, ester acrylate, silicone acrylate, epoxy acrylate, acrylatesincluding methacrylate, silicone, urethane, epoxy or the like. Theparticulate thermoplastic filler may be polyolefin, polyvinyl chloride(PVC), a copolymer of vinyl chloride and at least another monomer, or apolyester such as polyethylene terephthalate (PET). The particulatethermoplastic filler may be a compound or a blend comprising athermoplastic polymer such as PVC or a vinyl chloride copolymer. Forexample, an exemplary composition may comprises urethane acrylate as thebasic polymer resin, and a filler of PVC modified with a copolymer ofvinyl chloride and at least another monomer such as vinyl ester or vinylether. The crosslinkable composition 16 is cured to form a crosslinkedcomposition. Examples of curing method include but are not limited tothermal and radiation curing. In some embodiments, thermal curing occursduring a thermal lamination process.

In some embodiments, the exemplary core layer structure 180 is furtherlaminated with at least one printable thermoplastic layer and atransparent film. The resulting laminated structure is then cut to forma plurality of information carrying cards. In some embodiments, thepressure is preferably less than 2 MPa. The temperature is in the rangeof 65-232° C. in some embodiments, and is preferably less than 150° C.in some embodiments in the lamination process.

Rectangular shaped information carrying cards or smart cards in thisdisclosure are for illustration only. The disclosure structure andprocess of making also apply to any information carrying card or part ofany shapes and any size. Examples of these parts include but are notlimited to rectangular sheets, circular sheets, strips, rods and rings.The size includes but is not limited to any size following ISO/IEC 7810standard.

Although the subject matter has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be construed broadly, to include other variants and embodiments,which may be made by those skilled in the art.

What is claimed is:
 1. A method of forming a credential card,comprising: positioning a first thermoplastic layer in a stackedarrangement with a first release sheet; applying a cross-linkablepolymer composition to the first thermoplastic layer; positioning aninlay layer in a stacked arrangement with the first thermoplastic layerand the first release sheet, wherein the inlay layer is in directcontact with the first thermoplastic layer and the cross-linkablepolymer composition, and wherein the inlay layer defines at least onecavity; positioning a first circuit element within the at least onecavity defined by the inlay layer; positioning a second release sheet ina stacked arrangement with the first thermoplastic layer, first releasesheet, and inlay layer to form a layered structure; applying apredetermined pressure to the layered structure; and heating the layeredstructure to a temperature sufficient to at least partially cure thecross-linkable polymer composition to form a credential core.
 2. Themethod of claim 1, wherein the inlay layer comprises metal.
 3. Themethod of claim 1, wherein the first circuit element comprises a printedcircuit board having at least one electronic component formed on asupporting film.
 4. The method of claim 1, wherein the first circuitelement comprises an antenna.
 5. The method of claim 1, comprising:positioning a second thermoplastic layer on a first side of thecredential core; positioning a third thermoplastic layer on a secondside of the credential core, wherein the second thermoplastic layer, thecredential core, and the third thermoplastic layer form a card stack;laminating the card stack under a predetermined pressure at apredetermined temperature to form a credential card.
 6. The method ofclaim 5, wherein at least one of the second thermoplastic layer and thethird thermoplastic layer comprises a printable thermoplastic layer, atransparent thermoplastic layer, or both a printable and transparentthermoplastic layer.
 7. The method of claim 1, wherein the firstthermoplastic layer comprises a polyvinyl chloride (PVC) material.
 8. Acredential card core, comprising: a first thermoplastic layer; across-linkable polymer composition disposed on at least a portion of thefirst thermoplastic layer; an inlay layer positioned in a stackedarrangement with the first thermoplastic layer, wherein the inlay layeris in direct contact with the first thermoplastic layer and thecross-linkable polymer composition, and wherein the inlay layer definesat least one cavity; and a first circuit element positioned within theat least one cavity defined by the inlay layer.
 9. The credential cardof claim 8, wherein the inlay layer comprises metal.
 10. The credentialcard of claim 8 wherein the first circuit element comprises a printedcircuit board having at least one electronic component formed on asupporting film.
 11. The credential card of claim 8, wherein the firstcircuit element comprises an antenna.
 12. The credential card of claim8, comprising: positioning a second thermoplastic layer on a first sideof the credential core; positioning a third thermoplastic layer on asecond side of the credential core, wherein the second thermoplasticlayer, the credential core, and the third thermoplastic layer form acard stack; laminating the card stack under a predetermined pressure ata predetermined temperature to form a credential card.
 13. Thecredential card of claim 12, wherein at least one of the secondthermoplastic layer and the third thermoplastic layer comprises aprintable thermoplastic layer, a transparent thermoplastic layer, orboth a printable and transparent thermoplastic layer.
 14. The credentialcard of claim 8, wherein the first thermoplastic layer comprises apolyvinyl chloride (PVC) material.
 15. A method of forming a credentialcard, comprising: positioning a first thermoplastic layer in a stackedarrangement with a first release sheet; applying a cross-linkablepolymer composition to the first thermoplastic layer; positioning aninlay layer in a stacked arrangement with the first thermoplastic layerand the first release sheet, wherein the inlay layer is in directcontact with the first thermoplastic layer and the cross-linkablepolymer composition, and wherein the inlay layer defines at least onecavity; positioning a first circuit element within the at least onecavity defined by the inlay layer; positioning a second release sheet ina stacked arrangement with the first thermoplastic layer, first releasesheet, and inlay layer to form a layered structure; applying apredetermined pressure to the layered structure; heating the layeredstructure to a temperature sufficient to at least partially cure thecross-linkable polymer composition to form a credential core; andlaminating, subsequent to heating the layered structure, a card stackunder a predetermined pressure at a predetermined temperature to form acredential card, wherein the card stack comprises the credential coreand at least one additional thermoplastic layer.
 16. The method of claim15, wherein the inlay layer comprises metal.
 17. The method of claim 15,wherein the first circuit element comprises a printed circuit boardhaving at least one electronic component formed on a supporting film.18. The method of claim 15, wherein the first circuit element comprisesan antenna.
 19. The method of claim 15, wherein the at least oneadditional thermoplastic layer of the card stack comprises a printablethermoplastic layer, a transparent thermoplastic layer, or both aprintable and transparent thermoplastic layer.
 20. The method of claim15, wherein the first thermoplastic layer comprises a polyvinyl chloride(PVC) materia